Re: [Qemu-ppc] [PATCH] spapr-pci: remove io ports workaround

[Alexander Graf]

Am 16.07.2013 um 10:37 schrieb Alexey Kardashevskiy <address@hidden>:

> On 07/16/2013 06:32 PM, Alexander Graf wrote:
>> 
>> 
>> Am 16.07.2013 um 08:20 schrieb Paolo Bonzini <address@hidden>:
>> 
>>> Il 16/07/2013 07:19, Alexey Kardashevskiy ha scritto:
>>>> In the past, IO space could not be mapped into the memory address space
>>>> so we introduced a workaround for that. Nowadays it does not look
>>>> necessary so we can remove the workaround and make sPAPR PCI
>>>> configuration simplier.
>>>> 
>>>> This also removes all byte swappings as it is not PHB's to take care
>>>> of endiannes - devices should do convertion if they want to. And almost
>>>> every PCI device which uses IO ports does that by registering IO ports
>>>> region with memory_region_init_io() (Intel e1000, RTL8139, virtio).
>>>> 
>>>> However VGA uses MemoryRegionPortio which does not support endiannes
>>>> but it still expects the convertion to be done. For this case only,
>>>> this patch adds LITTLE_ENDIAN flag to portio_ops. Tests on PPC64 show
>>>> that other devices are not affected by this change. x86 systems should
>>>> not suffer either as having LITTLE_ENDIAN there has no effect.
>>>> 
>>>> Signed-off-by: Alexey Kardashevskiy <address@hidden>
>>>> ---
>>>> 
>>>> This removes bugs at least from SPAPR so any further fixes should be equal
>>>> for all platforms and hopefully will break all platform altogether but not
>>>> just PPC64-pSeries :)
>>>> 
>>>> Did I miss anything here?
>>> 
>>> No, I don't think so.  The patch looks good.
>> 
>> ... and will break all Mac targets again, no? Not to speak of non-ppc 
>> devices.
> 
> 
> Like what? I do not mind/argue/discuss, may be it breaks, I am just looking
> for good examples to test.

How about you start with

$ qemu-system-ppc

Then? It shouldn't show a prompt with your patch ;)


Alex

> 
> 
> 
> -- 
> Alexey